There are plenty of challenges to overcome in Honkai Star Rail, but the true test of strength lies late into the first act of the game. Players who want to push their best team compositions to their absolute limits usually won't get much of a chance to do so outside of quest-related boss fights and Herta's SImulated Universe. That is until they unlock the Forgotten Hall.
The Forgotten Hall is, for all intents and purposes, the Spiral Abyss of Honkai Star Rail. There are tough enemies, random modifiers, and two-team setups that'll test the synergies between characters. This end-game activity is the premier proving ground for the game. However, to unlock the Forgotten Hall, players need to finish the Fleeting Lights quest from Pom-Pom first.
How to Unlock the Forgotten Hall in Honkai Star Rail (Fleeting Lights Quest)
Fleeting Lights only becomes available to the player once they reach Trailblaze Level 21, so expect to sink a bit of time into the game first before reaching this point. Also, players need to finish their first Trial of Equilibrium, which opens up at Trailblaze Level 20.
After reaching the appropriate level, Pom-Pom will send the Trailblazer a message saying that he's sensing a weird disturbance inside the Astral Express. Pay him a visit, and the Fleeting Lights quest will officially start.
Luckily, there isn't much to do here. It mainly involves following the objective pointer, talking to the Express' crew, and interacting with the spooky, broken mirror standing on a quiet corner of the Parlor Car. Touch it, and the Messenger will appear before the Trailblazer. They will explain everything, from their goal to the existence of the mirror that leads to the Forgotten Hall. The Messenger will also ask the player to keep her presence a secret from the other passengers.
The final step of Fleeting Lights does give players the option to rat the Messenger out, but this is mostly just for show. Nothing of consequence happens regardless of what choice the player makes, and the Forgotten Hall in Honkai Star Rail will be accessible from there on out.
The Forgotten Hall features 15 stages of increasingly-difficult combat encounters. Most of the time, players will only have to worry about defeating all enemies within a certain number of turn cycles, which means exploiting enemy elemental weaknesses is going to be a major priority when it comes to building Hall teams. Earn three stars for a combat encounter to get 200 Stellar Jades and a boatload of Credits.
Honkai Star Rail is available on PC, Android, and iOS. A PlayStation version is in the works.